Immigrant advocacy groups are suing the federal government over accusations that border agents have engaged in ethnic profiling and abuse of immigrants and U.S. citizens.

The groups filed complaints and lawsuits this week.

The groups alleged Wednesday that officers at Dulles International Airport outside Washington, D.C., were complicit in sending a 4-year-old American girl to Guatemala without giving her parents a chance to retrieve her. Officers also detained a naturalized citizen who had worked with farm workers in New York, kept women in cold detention cells in Texas and lied on an arrest report that led to an undocumented immigrant's detention in Washington state, the advocacy groups said.

The complaints are the latest in a series of legal actions taken against U.S. Customs and Border Protection and U.S. Border Patrol from immigrant advocacy groups, who have long sought to reform the agency's conduct on the southern and northern border. The cases involve federal administrative complaints against the agency and lawsuits filed in federal court.

Some seek monetary damages.

"By filing these cases, we're aiming to send a message to CBP that it's not above the law," said Trina Realmuto of the Boston-based National Immigration Project.

A statement from CBP said the agency can't comment on pending litigation, but noted that it stresses honor and integrity from its officers and agents.

"We do not tolerate misconduct or abuse within our ranks and we fully cooperate with all investigations of alleged unlawful conduct, on or off duty, by any of our CBP employees and contractors," the statement said.

One of the cases is that of Emily Ruiz, who at four years old was sent to Guatemala after her flight to Kennedy Airport was diverted to Dulles. The girl was traveling with her grandfather, who was denied entry because of an immigration infraction two decades earlier.

The agency said the girl's parents, who are undocumented immigrants, opted to have their daughter returned to Guatemala rather than pick her up, possibly because they were concerned they would confront questions about their own residency status.

The family's attorney said the parents weren't given the chance to reunite with their daughter. It took five months for the girl to return to her home in New York..

Another case outlined is of Lucy Rogers, a naturalized U.S. citizen who works with farm workers in New York. Rogers said Border Patrol agents pulled her over in late 2011 without reasonable suspicion, only saying he was conducting a "citizenship checkup."

The two farm workers traveling with her couldn't provide identification, so the agent took all three into custody. She was arrested on suspicion of trafficking people, questioned and held for several hours at the station. She alleges her car navigation device was seized for seven months.

The group also filed four complaints on behalf of undocumented immigrants who were detained in Texas holding cells. They allege the cells are kept at cold temperatures, don't have enough beds or bathrooms and aren't sometimes given cups to drink tap water. They allege some of the immigrants were in the holding cells for as long as six days.

In another case in Texas, an American woman crossing the border in Brownsville in late 2012 was forcibly thrown on the ground and injured by an agent during a search, according to advocates. The woman, Laura Mireles, was treated by paramedics for her injuries and released without being charged, the complaint alleged.

In Washington state, Gustavo Vargas Ramirez is suing the agency because he alleged a Border Patrol agent lied on his report to justify his arrest.

In that case, an Anacortes, Wash., police officer pulled the man over for a traffic infraction in 2011. The police officer called Border Patrol during the stop and an agent instructed the officer to put Vargas Ramirez on the phone. The man declined to answer any questions over the phone unless an attorney was present. The agent then instructed the police officer to arrest Vargas Ramirez because there weren't any records he was a legal resident, the complaint said.

Attorneys for Vargas Ramirez said the Border Patrol agent then said he was at the scene of the arrest and that he was called to provide language interpretation, even though the officer and Vargas Ramirez communicated without trouble. The complaint alleges that the police report filed by the officer who pulled Vargas Ramirez contradicts the Border Patrol report.

"Whether someone is a citizen or non-citizen, doesn't give the Border Patrol any legal justification to unlawfully arrest someone or beat them up. The constitution and laws govern all folks, not just those with legal immigration status," said Matt Adams of the Seattle-based Northwest Immigrant Rights Project. He is representing Vargas Ramirez.

Representatives of the National Border Patrol Council -- the union representing 17,000 agents -- did not immediately return a message Thursday seeking comment.

Previously, union vice president Shawn Moran had said "interest" group activism against the Border Patrol is taking a toll on the morale of agents and that Border Patrol agents don't target specific types of people, except those violating the nation's immigration laws.